Daily Water Intake Calculator

This gives a reasonable daily estimate for healthy adults. It is not medical advice.

Your details

Units

Sex

Body weight

Baseline method

You can nudge this based on thirst and climate

Exercise minutes per day

Exercise intensity

We add more water for longer and harder sessions

Climate adjustment

Bottle size

mL per bottle

Pregnant

Adds about 300 mL per day

Breastfeeding

Adds about 700 mL per day

All calculations run in your browser.

Baseline uses 30–40 mL per kg as a practical range. Many people land near 35 mL per kg.
For exercise we add about 8 oz per 30 minutes of light activity, 12 oz for moderate, and 16 oz for intense.
Hot or humid weather increases needs. Listen to thirst and adjust.
If you have kidney, heart, or other medical conditions, ask a clinician for personal guidance.